Jan. 5, 1954
SYNTHESIS AND POLYMERIZATION OF ALLYLESTERS OF CARBAMIC ACID
the addition of 5 ml. of trifluoroacetic acid to the reaction mixture. 4,4-Dinitroheptanedinitrile.-In a 500-ml. three-necked flask was placed 50 g. (0.3 mole) of 2,2-dinitro-1,3-propanediol, 320 ml. of water and 5 g. (0.09 mole) of potassium hydroxide. Over a period of 30 minutes, 90 ml. (1.35 moles) of acrylonitrile was added dropwise, while the temperature was kept a t 30'. After the addition of acrylonitrile was complete, the solution was stirred for 6 hours, during which time it turned red. Enough 30% potassium hydroxide was added to bring the PH to 8, and then the solution was stirred for another 3 hours. The reaction mixture became heterogeneous, consisting of a red aqueous phase and a deep red, dense oil. Extraction of the aqueous phase with three 75-1111. portions of ether gave a solid when the ether had evaporated. Recrystallization of the solid from methanol yielded two crops of crystals, weighing 7.75 and 1.65 g., m.p. 78". The heavy oil was triturated with 25 ml. of ether, and this treatment caused solidification. The solid was collected on a suction filter and freed of adhering oil. Recrystallization from methanol yielded two crops of crystals weighing 8.61 and 2.75 g., m.p. 77-78'.16 The total weight of 2U.iii g. represented a yield of 37%, . - based on 2,2~dinitro-l,3-propanediol. N-Bis-(2-cvanoethvl)-trifluoroacetamide.-A round-bottomed flask w& fitted with a reflux condenser, the top of which was connected to a trap surrounded by a Dry Ice-acetone-bath. Any vapors which passed through the condenser would thus liquefy in the cold trap. A solution of 50 g . of trifluoroacetic acid and 92 g. of benzoyl chloride was heated in the flask, and when the temperature reached 65", gas was evolved. Over a period of 2 hours, the temperature was raised to 180°, and all substances boiling below 15' condensed in the cold trap. The product was mainly trifluoroacetyl chloride, mixed with some hydrogen chloride. A solution of 100 g. of @,P'-iminodipropionitrile in 50 nil. of chloroform was rapidly stirred while the crude trifluoroacetyl chloride was distilled into it. A white solid immediately formed and the reaction was carried on for 5 hours. The solid was filtered off, and it T Y ~ Sidentified as the hydrochloride of P,P'-ixninodipropionitrile"; 66 g. was obtained. After the chloroform had been removed from the filtrate, the residue was distilled through a 12" \-igreux column, yielding a water-white liquid boiling a t 138" a t 0-1 mm., W2"D 1.4394. Anal. Calcd. for CsH80F&;3: C, 43.83; H, 3.68; Ii, 19.14. Found: C, 43.97; H, 3.39; h-,19.40. N-Bis-(2-cyanoethyl)-3,5-dinitrobenzamide.-A solution of 4.92 g. (0.04 mole) of PJ'-iminodipropionitrile in 20 ml. of chloroform was cooled and rapidly stirred. Upon the addition of 4.55 g. (0.02 mole) of 3,5-dinitrobenzoyl chloride dissolved in 30 ml. of chloroform, a white solid formed. Stirring was carried on for 2 hours, and then the solid was
[COKTRIBUTION
107
removed by filtration. The total weight (dry) was 8.8 g.; the solid was a mixture of the desired product and the hydrochloride of P,fi'-iminodipropionitrile. The product was extracted with water to remove the soluble hydrochloride, leaving behind 5.4 g. of a tan solid melting a t 123-126'. Recrystallization from ethanol yielded short needles melting a t 144-145°. When this solid was mixed with pure @,P'iminodipropionitrile hydrochloride (m.p. 147-148") melting occurred a t 134-136" with the development of a green color. Thus, the desired X-bis-(2-cynnoethyl)-3,5-dinitrobenzamide melts close to P,P'-iminodipropionitrile hydrochloride. Anal. Calcd. for C I ~ H ~ I O ~ N C,B 49.22; : H , 3.19; N, 22.08. Found: C, 49.90; H, 3.70; X, 21.64. N-Bis-(2-cyanoethy1)-benzylamine.-A solution of 24.6 g . (0.2 mole) of P,P'-iminodipropionitrile and 12.7 g. (0.1 mole) benzyl chloride in 30 ml. of chloroform was stirred and heated to reflux for 12 hours. A solid slowly formed, and this was removed by suction filtration. As the chloroform solvent was removed, more solid formed, which was identified as the salt of @,P'-iminodipropionitrile, and this too was removed by _filtration. The dense yellow residue was cooled to -(.!io, but no crystals appeared. Distillation through a short S'igreux column gave a very pale liquid boiling a t 176' and 0.8 mm., ? z 2 0 ~ 1.5278. This was identified as N-bis-(2-cyanoethyl)-benzylamine. Anal. Calcd. for CISHIJN~:C, 73.21; H, 7.09; S, 19.70. Found: C, 73.45; H, 7.14; N, 19.81. Attempted Polymerization of N-Bis-( 2-cyanoethy1)-benzylamine with Formaldehyde.-A solution of 0.195 g. of strioxane (6.5 mmoles of HCHO) and 1 ml. of concd. sulfuric acid in 5 ml. of 90% formic acid was warmed to 30-35'. During the addition of 1.36 g. (6.4 mmoles) of N-bis-(2cyanoethy1)-benzylamine, the temperature rose and an ice-water bath was used to keep it a t 30-35". After stirring for 75 minutes, the clear solution was poured into 50 ml. of water a t 5', but no solid material formed. No solid was obtained when a sample of the solution was treated with sodium chloride. However, when the solution was basified with excess 20% aqueous sodium hydroxide, a milky emulsion formed. This mixture was extracted with ethylene chloride, which cleared up the emulsion. Removal of the ethylene chloride left behind 1.09 g. of a dense liquid which was identified as N-bis-(2-cyanoethyl)-benzylamineby its refractive index.
Acknowledgments.-JVe are indebted to the Office of Naval Research for the financial support of this work and we wish to thank Mrs. M. Wyrnan for technical assistance. LAPAYETTE, INDIANA
h-0. 195 FROM THEGOODYEAR RESEARCH LABORATORIES]
The Synthesis and Polymerization of Some Allyl Esters of Carbamic Acid BY C. E. GLEIX RECEIVED JULY 16, 1953 A number of allvl esters of carbamic acid have been svnthesized. Their properties, as well as those of some of their polymers, are reported.
A convenient method of synthesizing allyl carbamates is the reaction of allyl chloroformate with amino compounds. The reactions are generally carried out a t a temperature of 0 f 10' in the presence of pyridine as an acid acceptor. A general procedure for their preparation is the dropwise addition of the chloroformate with stirring to a cold solution of the amino compound in pyridine. The resulting mixture is then poured into cold dilute hydrochloric acid from which the carbamate is separated, washed with dilute sodium bicarbonate solution, and purified.
The aldehyde condensation derivatives of the carbamates are prepared by treating an aldehyde with a carbamate in the presence of an acid catalyst. The general procedure for their preparation is the addition of an acid catalyst with cooling to a stirred solution of the aldehyde and carbamate followed by the addition of water, neutralization and purification. Table I lists the allyl carbamates which have been prepared and indicates the source of each ester as well as the percentage yield. Certain physical properties of the esters are reported in Table 11.
c. E. GLEIhl
1U8
1’111, i ( i
TABLE I OF CARBAMIC ACID ALLYLESTERS Yield,
Ester
I I1
Allyl carbamate“ Allyl ( N-carballyloxy)-carbamate)b
I11
Ethylene bis-( S-carballyloxycarbamate)C
IV VI VI1
Bis-( N, ?i’-carballyloxy)-uredd illlyl (N-allyl)-carbamate Bis-( N,N’-carballyloxy ) hydrazine” Allyl ( N-carballyldioxy)-carbamate’
VI11
Allyl ( S-allyloxy )-carbamate
IX X
( S-Carballyldioxy j ( N’-carballvloxy)-urcag ( S-Carballyloxy)-ethylenediamiIieh,~ Bis-( S,S’-carballyloxy)-ethyleiiedianiine”2 Allyl (N-methylo1)-carbarrlate Allyl ( S-carballyldioxymethyl)-carI~a~m~~e Allyl ( N-carbaIlyldioxyethy1)-cartwnate’ Allyl bis-( S-carballyldioxyethy1)-carbamate 411yl (S-carballyldioxymethyl, methyl l-cn mate Allyl (N-carballyldioxyphenyl )-carbaniate’ Allyl (S-carballyloxymethyl)-carbatnute“
i-
XI XI1 XI11 XIV XV xl-I
Source R 85 Allyl chloroformate and ammonia in benzene 18 Allyl chloroformate and allyl (N-sodium) carbamate, or ( Xi-carbally1oxy)-carbamyl chloride and allyl alcohol 5.5 ( S-Carbally1oxy)-carbamyl chloride and ethylene glycol, or ethylene bischloroformate and allyl (5-sodium)carbamate -00- Allyl carbamate and phosgene 70 .411yI chloroformate and monoallylaminc 93 Allyl chloroformate and hydrazine hydrate i o Allyl chloroformate and (S-hydroxyl allyl carbaniate, prepared from hydroxylamine and allyl chloroformate in aqueous sodium carbonate 31 Allyl chloride and the sodium derivative of allyl (N-hydroxyl) carbamate Allyl chloroformate and hydroxylurea IXallyl carbonate and ethylenediamine Diallyl carbouate and ethylenediamine Allyl carb:imate and formaldehyde in aqueous L C O , Allyl chloroformate m t l allyl (S-niethylol~-c:rrb:ttnatc Allyl chloroformate ittic1 irionoethanolarnine Allyl chloroforinate atid diethauolamirie
Allyl chloroformate and aldehyde ammonia Allyl chloroformate and p-aminophenol *4Ilyl alcohol and (S-carbally1oxy)-aminoacetate, ])repared in 2370 yield from allyl chloroformate and methyl aminoacetate Bis-( S,X ‘-carbally1oxy)-riiethylenediaiiiiiic’ ti0 Allyl carba.inate, forrnaliu and a trace of hydrogetl XIS chloride XS Bis-(S,S‘-carbal1yloxy)-methyl, -methylenedi80 Allyl carbam:tte, acet:tldehyde and a trace of dilute hydrochloric arid amine x iI Bis-( S,S’-carballyloxpj furyl, I:iethylctiediamine 90 Allyl carbarnate ai111 furfurd in glacial acetic ;xiti Allyl anhydroformaldehyde-carbamate MX Allyl carbamate, formalin and concd. hydrochloric x i r l SXII Allyl anhydroacetaldehyde-carbamate 00 Allyl carbamate, acetaldehyde and concentrated hydroS S III chloric acid xn\. Allyl ~nhydrocitral-cdrbalrlate (i3 Allyl carbamate, citral and glacial acetic acid 30 Allyl cnrhainate, glyoxal and conctl. hydrochloric acid X X 1. Allyl anhydroglyoxal-carbamate SL‘ Mcthacrylarnidc, allyl ~ ~ l c o l ~a11d o l potassium h y l ~ o XS\’I Allyl (S-isopropenyl)-carharnate broniite solution .411yl iS-jotlium)-carl)~rrl~:lteand acrylyl chloride i i i SX\’Il benzeiie S X Y I I I Allyl (S-cyario)-carl~ainatc 30 Allyl chloroforinatr ant1 cy:tnainide SXIX iS-Carba1lyloxy)-urea 50 Allyl chloroformate ant1 urea or (K-carballylosy )carbamyl chloride arid murnonia in ether * C. E. Gleim, C . S.Patent 2,541,646;. A . G . Chrtiicek, U . S. Patent 2,401,549. “_ C. E. Gleim. U. S.Patent 2,483,194. C. E. Glcim, U. S. Patent 2,579,426. SVhitehill, U. S. Patent 2,583,980. A . G. Chenicek, U. S. Patent2,394,592. e L. 9. * K. IV. Rosenmund, German Patent 676,049. J . G . Lichty a n d N. V. Seeger, LT,S. 0 C. E. Gleim, U. S.Patent 2,579,427. .4.G. C . E.Glciin, LT. S.Patent 2,508,249. Patent 2,464,519. i I. E . Muskat and F. Strain, U . S. Patent 2,390,551. Chenicek, U. S. Patent 2,385,911. XVII XVIII
The polymer of anhydroformaldehyde allyl carbamate was studied most extensively since it is easily prepared from relatively cheap raw materials. The colorless, transparent, insoluble and infusible polymer has a Rockwell “M”hardness of 98 and was prepared by heating the monomer (which may exist as a dimer or trimer) in an oven maintained a t 3.5’ for 20 hours in the presence of 2.5% of benzoyl peroxide. A slightly modified -4.S.T.M. method of testing showed the polymer to be insoluble i n :icetone, 957G ethanol, gasoline, carbon tetrachloride, toluene and ethyl acetate. It is also insoluble in ;30yosulfuric acid and 1O?;, solutions of sodium
hydroxide, hydrochlvric acid aiitl nitric acid. I t is attacked strongly, however, by concentrated nitric and sulfuric acids. Tables 111, I V and V offer a comparison of certain properties of anhydroformaldehyde allyl carbamate with those of other polymeric materials. The conditions used for the polymerization of some other allyl esters of carbanic acid are listed in Table VI. The monoallyl esters formed thermoplastic polymers whereas the diallyl esters formed transparent polymers of the insoluble and infusible type. The Rockwell “M”hardness of the polymers varied from SO to 10.5 with the esceptioli of ;1
Jan. 5, 1954
10'3
SYNTHESIS AND POLYMERIZATION OF ALLYLESTEKS OF C~AIZUAMICI ACID TABLE I1 PHYSICAL PROPERTIES OF ALLYLESTERS OF CARBAMIC ACID B.P..
OC.
Mm.
73.5 145-147d
2 3
84.5-85
3
Ester
I I1 I11 IV V VI VI1 VI11 IX X XI XI1 XI11 XIV XV SVI XVII XVIII XIX XX XXI
M.p.,c QC.
1 ,4520 1.4728
70 1 ,4566
88-89 143-145 90-92
3 2
160
2
1 ,4558 1.4569 62-63 1.4775 89-90
a
1.4818
a
151-152
3
165-170b
3
126-128
1
1.4630 1 ,4667 1.5600 89-90.5 1 ,4653 108-1 09 105-106 140.5
XXII
185b 2 1.4870 XXIII XXIV 163-1 73' 2 1.5170 a XXV XXVI 2 1.5398 60 XXVII 150-160b 2 1.4653 XXVIII 162-1 63 161-162 XXIX a Decomposes on heating. With decomposition. Uncorrected. C. SAL, 71, 1044 (1949), m.p. 43-45",
'
Polymer, s p . gr. 2.50 1.31 Sp. pr. change during cure, % 15.20 Benzoyl peroxide concn., % 2 5 Rockwell "M" hardness 95 Tensile, p s i 6500 5000 Modulus of elasticity, p.s.i. 1,000,OM) 240,000 6500 10,000 Modulus of rupture Abrasion resistanceQ 1 6.5 ~~
Methyl methacrylate (Plexiglass) 0.945
1.19
1.32
"."
3.0
25.g0
0.2-0.5
91
8_ R_
6000 270,000
7500 400,000 14,000 12.1
9,000 1.1
dr
O C
N Analyses, % Calcd Found
13.82 13.87 7.59 7.57 9.62 8.85 11.80 12.30 28 28 9.63 0.997 9.93 14.00 14.95 1.163 6.96 6.48 28 26 8.92 9.15 30 1.066 30 11.00 11.45 1.674 19.95 19.45 26 26 11.44 12.28 10.30 28 1.120 28 10.69 7.20 6.50 1.142 5.83 28 28 6.11 20 1.159 3.56 4.30 30 25 6.11 6.18 4.55
